Widely-used pesticides are killing bees

Mar 29, 2012
by Heather Pilatic

Bees are still dying and EPA is still sitting on its hands. Luckily for those of us who like to eat, scientists have been hard at work cracking the "mystery" of colony collapse disorder (CCD). Today two new studies were published in Science, strengthening the case that neonicotinoid pesticides are indeed key drivers behind recent pollinator declines.

To avoid in advance some of the inevitable confusion on this topic, nobody is saying that neonicotinoids are the culprit behind CCD. Most scientists now believe that we have been losing more than a third of our hives each year since 2006 from a combination of factors acting in concert: pathogens, pesticides and nutritional stress. The debate has lately been over which is the more critical catalyst, and in the last year pesticides have rapidly risen to the top.

Regulators in the U.S. remain paralyzed by this debate, despite ongoing public demand for decisive action.

Today's studies come on the heels of a year of damning evidence for these pesticides: threeseparatestudies in the last year confirmed that low-level exposures to neonicotinoids synergize with a common pathogen to dramatically increase bees' susceptibility to infection and the likelihood of death. In one long-awaited study published in January, exposure levels were so low as to be undetectable. And Italian researchers have proven, yet again, that in a single flight over freshly-sown corn fields, bees can be exposed to neonicotinoid-contaminated dust from planters depositing treated seeds at acutely toxic levels. This means they die right away. These same researchers have shown in 2010 and 2011 that sub-lethal exposures impair bees' learning and memory.